A medical school in the Japanese capital apologized Tuesday for altering the results of entrance exams to stop women from studying there.

An internal investigation found that Tokyo Medical University started manipulating the results in 2006 - or possibly earlier - because its leaders thought female students would leave their careers when they became mothers.

The investigation found that last year, the school reduced all applicants’ first-stage test scores by 20 percent, then added up to 20 points for male applicants. It said similar manipulations had been taking place for years.

Lawyers investigating the scandal said the university’s former chairman and president each received money from parents of prospective students whose entrance exam results were “padded," Japan’s Kyodo news agency reported.

The manipulation was revealed during an investigation into the alleged wrongful admission of a bureaucrat’s son in exchange for favorable treatment for the school in a ministry project. The bureaucrat and the former head of the school have been charged with bribery.

The school said the manipulation was wrong and would not happen again. It said it would consider retroactively admitting students who otherwise would have passed the exams, but did not explain how it would do so.

“We sincerely apologize for the serious wrongdoing involving entrance exams that has caused concern and trouble for many people and betrayed the public’s trust,” said Tetsuo Yukioka, the school’s managing director.

He denied any previous knowledge of the manipulation and said he was never involved.

“I suspect that there was a lack of sensitivity to the rules of modern society, in which women should not be treated differently because of their gender,” he said.

Yukioka said women were not treated differently once they were accepted, but acknowledged that some people believed women were not allowed to become surgeons.

Japanese women are among the most educated in the world, with nearly 50 percent having college degrees, but about 70 percent – according to media reports - leave their jobs after having children because working Japan’s long hours is no longer feasible, and a lack of adequate childcare. Women are also expected to do the majority of the housework and care for elderly relatives.

More than 55,000 Japanese children were waiting for kindergarten places this year, rising for the third straight year, the country’s welfare ministry said. The government plans to increasing the childcare spaces by 320,000 by 2021, the Japan Times reported.

Earlier this year, a Japanese woman was reprimanded by her boss for becoming pregnant before it was her “turn,” going against a timetable that dictated when women employees were allowed to marry and have children. according to media reports.